This invention relates generally to a sealed six-sided or parallelepiped carton which is formed by folding a generally rigid, unitary, die-cut blank, and more particularly to a carton of such character in which at least some of the corners are sealed by means which are a part of such blank to seal the contents of the carton and to thereby prevent the egress of the contents of the carton and the entry of oxygen and moisture from the atmosphere into the carton. The carton is adapted to contain particulate materials in direct contact with the inside surfaces of the carton and has an integral reclosable pour-out spout to permit the removal of a portion of such particulate materials and the subsequent reclosing of the carton. More particularly, this invention relates to a carton of such character in which the blank is formed from a polymeric material and, even more particularly, to such a carton in which such polymeric material is a composite material, a major portion of the thickness of which includes an expanded polymeric material.
Six-sided folding cartons are widely used for the packaging of many different kinds of particulate materials, such as breakfast cereals and powdered laundry detergents. One of the problems associated with the use of such cartons for these applications is the problem of removing only a portion of the contents of the carton. When only a portion of the contents of the carton is removed it is necessary to provide means to reclose the carton to prevent spillage of the remaining portion of the contents and in some cases to protect such contents from the deleterious effects of continuing contact with oxygen or moisture in the atmosphere. In many instances, for example in the case of the packaging of many breakfast cereals, this problem is solved by packaging the product in a plastic film or waxed paper bag which, in turn, is packaged in the folding carton. In such a carton, the contents are removed by opening an end of the carton to provide access to the inner bag, and this bag can be reclosed by folding after some of the contents have been removed therefrom. However, such a carton construction requires the use of the separate inner bag which adds to the cost of the materials used for the packaging application in question and to the complexity of the process for the filling of the carton. Further, in various prior art six-sided cartons, the use of such an inner bag is needed to help prevent oxygen and moisture in the atmosphere from entering the contents of the carton through the gaps or spaces which are normally formed at the corners of such cartons. Further, such cartons are usually formed by folding a generally rigid, unitary, foldable sheetlike material, a type of material that is permeable by moisture and/or oxygen from the atmosphere.
Another carton style which has proven to be popular for the packaging of some particulate materials, usually those which are relatively small in particulate size and excluding breakfast cereals, therefore, involves the use of a separate, movable pour-out spout which is attached to one of the surfaces of the carton in an opening therein. Such an attachment, which is usually made of a thin metal sheet, does permit the removal of a portion of the contents of a carton which does not include an inner bag, and the reclosing of such carton. However, again the use of a separate attachment adds to the cost and complexity of such a carton, and such attachments are generally rather small and are extensively utilized only in the packaging of particulate materials which are relatively small in size.
Generally, rigid polymeric materials, including expanded or foamed polymeric materials, offer many advantages over paperboard as a material of construction, including attractive appearance, relatively low cost, moisture imperviousness and good strength and rigidity characteristics in relationship to thickness and weight, and for these reasons these materials have captured important segments of packaging markets which were once held by paperboard. To date, however, polymeric materials have not been able to displace paperboard or other fibrous materials as the material of construction for folding boxes or cartons for breakfast cereals and other dry or particulate products to any great extent, at least in part due to the problems which relate to the sealing of the corners of such cartons.